From: Pekka Pessi <ppessi@xxxxxxxxxx>
The Tegra RCE (Camera) driver expects the mailbox to be empty before
processing the IVC messages. On RT kernel, the threads processing the
IVC messages (which are invoked after `mbox_chan_received_data()` is
called) may be on a different CPU or running with a higher priority
than the HSP interrupt handler thread. This can cause it to act on the
message before the mailbox gets cleared in the HSP interrupt handler
resulting in a loss of IVC notification.
Fix this by clearing the mailbox data register before calling
`mbox_chan_received_data()`.
Fixes: 8f585d14030d ("mailbox: tegra-hsp: Add tegra_hsp_sm_ops")
Fixes: 74c20dd0f892 ("mailbox: tegra-hsp: Add 128-bit shared mailbox support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pekka Pessi <ppessi@xxxxxxxxxx>
Signed-off-by: Kartik Rajput <kkartik@xxxxxxxxxx>
---
v2 -> v3:
* Updated commit description.
v1 -> v2:
* Added "Fixes:" tag in the commit message.
* Made similar change for 128-bit shared mailboxes.
---
drivers/mailbox/tegra-hsp.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index 8d5e2d7dc03b..c1981f091bd1 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -388,7 +388,6 @@ static void tegra_hsp_sm_recv32(struct tegra_hsp_channel *channel)
value = tegra_hsp_channel_readl(channel, HSP_SM_SHRD_MBOX);
value &= ~HSP_SM_SHRD_MBOX_FULL;
msg = (void *)(unsigned long)value;
- mbox_chan_received_data(channel->chan, msg);
/*
* Need to clear all bits here since some producers, such as TCU, depend
@@ -398,6 +397,8 @@ static void tegra_hsp_sm_recv32(struct tegra_hsp_channel *channel)
* explicitly, so we have to make sure we cover all possible cases.
*/
tegra_hsp_channel_writel(channel, 0x0, HSP_SM_SHRD_MBOX);
+
+ mbox_chan_received_data(channel->chan, msg);
}
static const struct tegra_hsp_sm_ops tegra_hsp_sm_32bit_ops = {
@@ -433,7 +434,6 @@ static void tegra_hsp_sm_recv128(struct tegra_hsp_channel *channel)
value[3] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA3);
msg = (void *)(unsigned long)value;
- mbox_chan_received_data(channel->chan, msg);
/*
* Clear data registers and tag.
@@ -443,6 +443,8 @@ static void tegra_hsp_sm_recv128(struct tegra_hsp_channel *channel)
tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA2);
tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA3);
tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_TAG);
+
+ mbox_chan_received_data(channel->chan, msg);
}
static const struct tegra_hsp_sm_ops tegra_hsp_sm_128bit_ops = {
--
2.34.1
